In a variety of medical procedures, a physician may need to occlude vessels in order to contain bleeding or reduce the risk of hemorrhaging.
There are a variety of devices that have been developed to occlude blood vessels. One of these employs a catheter to deliver one or more vaso-occlusion coils to a vascular target site. The vaso-occlusion coils are typically platinum or other surgical-metal coils that are delivered via a vascular catheter. Typically, the coil is placed in a linear condition in the catheter, and is pushed from the end of the catheter by a pusher wire. As the coil exits the delivery device it assumes a relaxed, convoluted shape at the vascular site.
The coil may be deployed simply by ejecting it from the distal end of the catheter. However, this technique may be unsatisfactory where it is desired to better position the coil in the vessel once it has been ejected from the catheter and has assumed its convoluted shape. To overcome this problem, various release mechanisms have been proposed to allow for positive release of the coil from the end of a pusher wire once the coil is properly positioned at the vascular site. Expandable jaw clamps and electrolytically erodible joints are examples of such mechanisms.
It would be advantageous to provide a coil delivery device and catheter assembly which provides the combined advantages of (i) a coil release mechanism that allows for simple coil loading and release, (ii) positive release once the coil is properly positioned at the target site, (iii) multiple reloading steps for placement of multiple coils at a selected target site, and (iv) operable with coils having a variety of coil diameters.